2100005 has 4 divisors (see below), whose sum is σ = 2520012. Its totient is φ = 1680000.

The previous prime is 2100001. The next prime is 2100011. The reversal of 2100005 is 5000012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1151329 + 948676 = 1073^2 + 974^2 .

It is not a de Polignac number, because 2100005 - 2² = 2100001 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2099965 and 2100001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 209996 + ... + 210005.

It is an arithmetic number, because the mean of its divisors is an integer number (630003).

2^2100005 is an apocalyptic number.

It is an amenable number.

2100005 is a deficient number, since it is larger than the sum of its proper divisors (420007).

2100005 is an equidigital number, since it uses as much as digits as its factorization.

2100005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420006.

The product of its (nonzero) digits is 10, while the sum is 8.

The square root of 2100005 is about 1449.1393997818. The cubic root of 2100005 is about 128.0580181319.

Adding to 2100005 its reverse (5000012), we get a palindrome (7100017).

The spelling of 2100005 in words is "two million, one hundred thousand, five".